Fixed syntax warning in line RedisGraph#48

Fixed warning for Python 3.8.5

redisgraph/query_result.py

@@ -45,7 +45,7 @@ def __init__(self, graph, response):
         if isinstance(response[-1], ResponseError):
             raise response[-1]
 
-        if len(response) is 1:
+        if len(response) == 1:
             self.parse_statistics(response[0])
         else:
             self.parse_results(response)